<!DOCTYPE html>
<html lang="en">

<head>
    <style>
        .box {
            border: 2px solid teal;
            height: 100px;
            line-height: 100px;
        }
    </style>
</head>

<body>
    <div class="box ">
        哈哈哈哈
    </div>
</body>

</html>